An in-plane-switching (IPS) mode liquid crystal display device is known as an example of display devices. An IPS mode liquid crystal display device includes a pair of substrates used to seal a liquid crystal layer therein, and a pixel electrode and a common electrode are provided with one of the substrate. In the IPS mode liquid crystal display device, a transverse field produced between these electrodes is used to control the alignment of the liquid crystal molecules in the liquid crystal layer. Further, a fringe field switching (FFS) mode liquid crystal display device is commercially used. In an FFS mode liquid crystal display device, a pixel electrode and a common electrode are arranged on different layers and a fringe field produced therebetween is used to control the liquid crystal molecules.
Here, a high-speed transverse field mode liquid crystal display device is known as a liquid crystal display device with faster response and improved alignment stability as compared to the conventional FFS mode one. In the high-speed transverse field mode liquid crystal display device, a pixel electrode and a common electrode are arranged in different layers and a slit is provided with the electrode which is closer to the liquid crystal layer to rotate the liquid crystal molecules in the proximity of the sides of the slit facing each other in its width direction such that the liquid crystal molecules at one side and the liquid crystal molecules at the other side are rotated in reverse.
As to such a high-speed transverse field mode liquid crystal display device, further improvement of the alignment stability is demanded.